Re: [boost] [variant] static_visitor has no virtual destructor.

Subject: Re: [boost] [variant] static_visitor has no virtual destructor.
From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2012-11-07 21:12:53

AMDG

On 11/07/2012 10:30 AM, Pierre Talbot wrote:
> Hello,
> 
> I have a compilation error with Boost (1.52) and g++ (4.7) with the flag
> -Weffc++:
> 

I would strongly advise against using this flag
with Boost.  For large parts of Boost, the rules
that -Weffc++ checks are simply not applicable,
and trying to comply with them would be a huge
burden for no gain.

> error: base class ‘class boost::static_visitor<std::basic_string<char>
>>’ has a non-virtual destructor [-Werror=effc++]
> 
> And the static_visitor class is defined with a protected non-virtual
> destructor:
> 
> template <typename R = ::boost::detail::static_visitor_default_return>
> class static_visitor
>     : public detail::is_static_visitor_tag
> {
> public: // typedefs
> 
>     typedef R result_type;
> 
> protected: // for use as base class only
> 
>     static_visitor() { }
>     ~static_visitor() { }
> 
> };
> 
> Is it normal ? And if it is, how to avoid this error ?
> 

In Christ,
Steven Watanabe